Explosive.



- it absorbs moisture.

UNITED STATES TENT OFFICE.

FIN SPARRE, OF WILMINGTON, DELAWARE, ASSIGNOR TO THE E. l. DU PONT DE NEMOURS POWDER COMPANY, OF WILMINGTON, DELAWARE, A CORPORATION OF NEW JERSEY.

EXPLOSIVE.

Specification of Letters Patent.

Patented Feb. 20, 1906.

Applicationfiled March 17, 1905. Serial No. 250,568.

To all whom it may concern.-

Be it known that I, FIN SPARRE, a subject of the King of Sweden and Norway, residing at Wilmington, county of Newcastle, and State of Delaware, have invented a new and useful Improvement in Explosives, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings, which form a part of this specification.

My invention relates to explosives consisting of an ammonium-nitrate or similar oxygen carrier base and a metallic ingredient. Heretofore nitrate-of-ammoniuni explosives have been made and used in large quantities particularly for blasting, but have always been used in loose form. The use of this explosive in loose form is unsatisfactory, for. the reason that it is too light to get the proper load in the bore and also for the reason that On the other hand,

* this explosive when compressed could not be detonated at all, and therefore notwithstanding the obvious advantages of using the explosive in compressed form it has been impracticable to do so on account of the impossibility of detonating it.

The object of this invention is to render the composition easy and sure of detonation with ordinary caps when in compressed form and to effect this without adding to the composition any substance which would make the explosive less safe.

The invention consists in the addition to an ammonium-nitrate metallic composition of nitrocellulose of any percentage or grade of nitration.

The invention also consists in the addition to an ammonium-nitrate metallic composition containing nitrocellulose of kerosene or other liquid hydrocarbon having properties similar to kerosene.

The invention also contemplates the addition to an ammonium-nitrate metallic composition containing nitrocellulose or containing nitrocellulose and a li uid hydrocarbon of a coating of paraffin a ter the explosive has been made into a cake or stick form. The addition of nitrocellulose to an ammonium-nitrate composition where the same is combined with a metallic ingredient renders the explosive easy of detonation when in compressed form. The term nitrocellulose usually refers in the art to a product made by the nitration of pure cellulose, such as cotton, or impure cellulose, such as sawdust. I As equivalents of nitrocellulose, however, I comprehend any substance having an equivalent chemical composition, such as that obtained by the nitration of starch or other bodies of the same molecular composition. I do not, however, comprehend any substances that contain nitrocellulose in a gelatinized formsuch, for instance, as liquid collodion, which is formed by dissolving soluble nitrocellulose in a suitable solvent. Such substances are physically and technically absolutely different from ungelatinized nitrocellulose and are impossible to use in my explosive, as they render detonation impossible nor do I comprehend nitroglycerin, which while it would render the composition easy of detonation when in compressed form would at the same timcconvert it into an unsafe composition liable to freeze, and therefore without the advantages inherent in an ammonium-nitrate metallic composition; nor do I mean to comprehend such substance as picric acid, which while it would maintain the composition safe and unfreezing would not impart to it ease of detonation in compressed form; nor do I comprehend ordinary nitro compounds-such asnitronaphthalene, nitrotoluol, &c. which do not impart to the composition ease of detonation in compressed form.

It is advisable to add to the foregoing composition, particularly when used in compressed form, a substance which will perform the function of allaying the dust in the manufacture ofthe composition and rendering the composition smoother during the compression. It is also advisable to add to the foregoing composition some carbonaceous substance, which will add strength to the compositionthat is, increase its explosive force. At the same time care must be taken to avoid the addition of any substance which would alfect the detonating power imparted to it by the addition of nitrocellulose. I find that a non-viscous liquid hydrocarbon that solidifies at a low temperature and boils at a high temperature, and more especially kerosene, which does not solidify at the lowest temperature attainable, exactly meets the requirements set out without diminishing the detonating capacity of the composition. Substances other than kerosene or an equivalent liquid hydrocarbon might be effective to perform the functions enumerated. For example, a viscous oil would be effective to allay the dust and impart smoothness to the composition; but its use is objectionable, because it would make the powder less easy to detonate, and therefore neutralize the advantages obtained by the addition of nitrocellulose, and because also such viscous oils solidify at too high a temperature. Kerosene also has the important advantage of making the composition less hygroscopic.

The foregoing composition is easy to compress and will retain its form after compression under all conditions of ordinary handling. It will be advantageous when the foregoing composition is in compressed form to dip the same into molten paraffin. Owing to the density of the composition when in compressed form, it absorbs so little of the paraffin as not to change, essentially, its composition, the efiect being merely to give the composition athin coating of paraffin, which serves to render the same still safer and still less hygroscopic and makes it readily avail able as an explosive agency in blasting in water.

The foregoing composition is. to be practically used in the same way'as ordinary explosives. It is safe, non-freezing, easy of detonation, of high enough density to give proper load, and may be blasted inwater. It can be made up in different degrees of strength. When a flame is applied to the explosive in the open air, it ignites with difliculty, and when ignited burns slowly. It is easily manufactured by mixing the ingredients in the ordinary way. Its strength is at least equal to if it does not substantially exceed that of .the strongest explosive now known, when the composition is made of the highest possible strength.

The explosive is not limited in its use to blasting purposes, but is available for use in shells and in other applications.

The compositions in which I purpose using both nitrocellulose and kerosene are about as follows:

Shell explosive: nitrate of ammonia, fiftyfive to seventy percent; aluminium, ten to twenty per cent.; nitrocellulose, ten to twenty-five per cent. kerosene, naught to ten per cent.

Trade "explosives: nitrate of ammonia, fifty to eighty per cent. ferrosilicon, five to twenty-five per cent. nitrocellulose, five to twenty-five per cent. kerosene, naught to ten per cent.

In the trade explosive in place of ferrosilicon I may use aluminium, or I may use a mixture of ferrosilicon and aluminium, or the ferrosilicon may be replaced by any metal of the ferrosilicon type.

Patent, is-

sulfid, carbid, or silicid of a metal, such as iron pyrites, carbid of silicon,,and the abovementioned ferrosilicon. All these substances act physically and chemically as' metal's, as

they raise the temperature of combustion, V

thus acting as a quickening agent to increase the force and velocity of the explosion. Nitrate of ammonia may be replaced in part by other oxygen-carriers, such as nitrate of soda or potash or nitrates or chlorates or perchlorates, which if used alone as the oxygencarrier would not be equivalents of nitrate of ammonia. The addition, however, of chlorates or perchlorates renders the composition less safe, and the complete substitution of a chlorate or perchlorate, even ofammonia, for the nitrateof ammonia would not be within the perview of my invention, as it would render the composition quiteunsafe and defeat the primary object of my invention.

While I prefer to include kerosene in the composition when the particular uses to which the explosive is to be put renders the advantages obtained by the addition of kerosene of great importance, its omission would sometimes be advisableas, for instance,

,when the explosive is used in coal mines,

where. a powder as fiameless as possible is de-- sired.

Having now fully described my invention, What I claim, and desire to protect by Letters 1. An ammonium-nitrate metallic explosive containing ungelatinized nitrocellulose.

2. An ammonium-nitrate metallic explosive containing ungelatinized nitrocellulose and a liquid hydrocarbon.

3. An ammonium-nitrate metallic explosive containing ungelatinized nitrocellulose and kerosene.

4. An ammonium-nitrate metallic explosive containing ungelatinized nitrocellulose, in compressed form.

5. An ammonium-nitrate metallic explosive containing ungelatinized nitrocellulose and a liquid hydrocarbon, in compressed form.

6. An ammonium-nitrate metallic explosive containing ungelatinized nitrocellulose and kerosene, in compressed form.

7. An ammonium-nitrate metallic exploammonium nitrate fifty to eighty per cent. of :1 metallic ingredient five to twenty-five per cent, and of nitrocellulose five to twentylive percent.

10. An explosive composition containing of ammonium nitrate fifty to eighty per cent, of a metallic ingredient five to twenty- Iive per cent, of nitrocellulose five to twentylive per cent. and of kerosene ten per cent. or

10 less.

11. An explosive composition containing ammonium nitrate, ferrosilicon and nitrocellulose.

In testimony of which invention 1 have hereunto set my hand, at Wilmington, De1a- I5 ware, on this 8th day of March, 1905.

FIN SPARRE. Witnesses:

CHARLES G. GUYER, M. BROWN. 

